1. Field of the Invention
The present invention generally relates to sewing machines of the type used in the garment industry. More particularly, the present invention is directed to a convertible sewing machine which is capable of performing plain-seaming as well as closed-seaming functions. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.
2. Description of the Related Art
Sewing machines have been a main-stay of the garment manufacturing industry for many years. In fact, since its invention, the sewing machine has become such an important tool in the garment industry, that many variations thereof have been developed. Nonetheless, most of these garment manufacturing sewing machines can be divided into two general classifications.
The first class of sewing machines may be termed "plain-seaming" sewing machines. Plain-seaming sewing machines are designed to sew two pieces of material to one another. A typical plain-seaming sewing machine is depicted in FIG. 1. As shown therein, the sewing machine primarily includes a housing which has a base plate, a working panel and a front panel. Further, a plain-seaming head-assembly is disposed at one end of the housing, and power and drive gears are disposed within the housing of the sewing machine. As shown in FIG. 1, the driving force for the machine is applied to a bent shaft 6 by a belt connected between an originating power source (not shown) and one end of shaft 6. This driving force will then be transferred through connecting rod 8 to a lower shaft 9 to cause rotation of lower shaft 9. The driving force is also transferred through the connecting rod 16 to the material-feeding shaft 25. Thus, once the initiating drive force is applied to bent shaft 6, the cooperation of the various components will initiate operation of the sewing machine.
A second class of sewing machines may be referred to as "closed-seaming" sewing machines. Closed-seaming sewing machines are used to sew the exposed edge of a piece of cloth to prevent the exposed fibers of the edge from fraying. A typical closed-seaming sewing machine is depicted in FIG. 2. As shown therein, the sewing machine includes a lower shaft 13 which receives a driving force from an initiating power source (not shown) via a drive belt, the belt causing rotation of lower shaft 13. The drive force is then transferred from lower shaft 13 to needle bar shaft 15 through connecting rod 14. This results in rotation of needle bar shaft 15 and reciprocation of needle bar 26. The needle bar 26 and the components associated therewith comprise a closed-seaming head-assembly which will operate upon the application of the initiating driving force to lower shaft 13.
Both closed-seaming and plain-seaming sewing machines are currently being widely used throughout the garment manufacturing industry. However, despite their wide-spread use and importance, the use of these machines is somewhat expensive, inefficient and inconvenient. The primary cause of such deficiencies resides in the closed-seaming and plain-seaming sewing machines taking the form of individually dedicated machines. Thus, the need for garment manufacturers to own and utilize both types of sewing machines has resulted in the reduced efficiencies noted above.
Therefore, there remains a need in the art for an improved sewing machine which overcomes the aforementioned deficiencies of the related art by providing a single sewing machine which is capable of performing both plain-seaming and closed-seaming functions.